Transport proteins (carrier proteins and channel proteins) allow substances into and out of the cell that cannot pass through the phospholipid bilayer (as they’re either to large, charged or not lipid soluble) by facilitated diffusion.
Specifically channel proteins allow ions into and out of the cell by creating a pore in the membrane in which they can move through with their concentration gradient
Answer:
when G1/S cyclin-CDK is activated. Expression of G1/S cyclins is regulated by E2F proteins
Explanation:
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Commitment to cell division occurs at Start when G1/S cyclin-CDK is activated. Expression of G1/S cyclins is regulated by E2F proteins in conjunction with pRB proteins.. Mitogens stimulated cell division by increasing the amount of G1 cyclins.
Cancer cells are the cells that divide rapidly than any other cells in the body. The drugs used in chemotherapy work on rapidly dividing cancer cells. Some cells of our body apart from cancer cells also divide rapidly along with the cancer cells such as the cells that line the stomach and the digestive tract. Chemotherapy drugs cannot differentiate the cancer cells and the normal cells so these drugs also attack the normal cells which divide rapidly along with the cancer cells. The drugs also attack the cells that are present in the roots of the hair. So, this results in the hair loss. Hair loss does not occur immediately after the chemotherapy treatment instead it starts after few treatments. The degree of the hair loss after chemotherapy depends on the drug type and process. So when the chemotherapy drugs are used it results in the hair loss and nausea.
Therefore, when chemotherapy drugs attack normal cells including the roots of the hair instead of cancer cells that divide rapidly along with the cancer cells it results in the hair loss and nausea.
Nitrogenous base, sugar and phosphate
